STi downpipe and Cobb stage 2 question
Thread Starter
Registered User
Joined: Apr 2005
Posts: 55
From: NW Florida
STi downpipe and Cobb stage 2 question
Is the STi downpipe catless or does it have a hi flow cat? I am about to get one but wanted to know if I could go to stage 2 with my AP if I get it. I like the stealth factor to it, but don't want to get it if can't go to stage 2.
Registered User
iTrader: (2)
Joined: Jul 2005
Posts: 147
From: The Wild Serengeti Suburbs of MAIC
Car Info: '08 WRB SG model D
Originally Posted by thunder_sti
sti stock downpipe has 1 cat...and the other is in the catback.
VIP Member
iTrader: (20)
Joined: Apr 2004
Posts: 1,019
From: Northern California
Car Info: 2018 Forester XT Touring (Dark Gray Metallic)
Originally Posted by lastlaugh
Is the STi downpipe catless or does it have a hi flow cat? I am about to get one but wanted to know if I could go to stage 2 with my AP if I get it. I like the stealth factor to it, but don't want to get it if can't go to stage 2.
http://cobbtuning.com/wrx/accessport-faq.html
Q. What is needed for Stage 2?
A. We actually field a lot of calls with people wanting the Stage 2 AccessECU because the dyno graph looks a lot better, but they do not have a turbo-back exhaust. Here is a diagram of the exhaust to help you visualize:
The Stage 2 was tuned on a car with a full turbo-back system. If you have pieced together a less than optimal combo of parts or those that were not designed to work together you may not get the full benefits of the Stage 2 AccessECU. Boost may not come on as quickly and the peak power may be down from those that have a well designed full turbo-back system. If you have replaced the first section (second cat or downpipe section) and nothing else, then the Stage 2 map is what we would recommend. Again the results will be far less than optimal, but it will control the boost better than the Stage 1. If you have replaced sections 2-4 (third cat, mid-pipe, and muffler section then you are still Stage 1. You managed to get all except the part that makes the most difference. Again, we want to reiterate that Stage 2 will only get the intended results with a well designed complete turbo-back.
Q. What is needed for Stage 2?
A. We actually field a lot of calls with people wanting the Stage 2 AccessECU because the dyno graph looks a lot better, but they do not have a turbo-back exhaust. Here is a diagram of the exhaust to help you visualize:
The Stage 2 was tuned on a car with a full turbo-back system. If you have pieced together a less than optimal combo of parts or those that were not designed to work together you may not get the full benefits of the Stage 2 AccessECU. Boost may not come on as quickly and the peak power may be down from those that have a well designed full turbo-back system. If you have replaced the first section (second cat or downpipe section) and nothing else, then the Stage 2 map is what we would recommend. Again the results will be far less than optimal, but it will control the boost better than the Stage 1. If you have replaced sections 2-4 (third cat, mid-pipe, and muffler section then you are still Stage 1. You managed to get all except the part that makes the most difference. Again, we want to reiterate that Stage 2 will only get the intended results with a well designed complete turbo-back.
Thread Starter
Registered User
Joined: Apr 2005
Posts: 55
From: NW Florida
Thanks fellas. I guess I got the STi Uppipe and downpipe confused. Its the Uppipe that is catless on the STi. Anyway, I ordered a Tsudo ETS downpipe off Ebay the other day. I saw a couple of reviews that were pretty good, and a friend of mine that has one recommended it too.
Registered User
iTrader: (2)
Joined: Jul 2005
Posts: 147
From: The Wild Serengeti Suburbs of MAIC
Car Info: '08 WRB SG model D
Yeah getting a used OEM STi uppipe is the best for the money...can get them around 50-60 bucks...some need to have the tack welds on the heat shield redone or reinforced otherwise they will shake loose and rattle. You can also spray it w/ a DEI heat spray before installing if you want to keep the heat inside and the outside cool.
FYI...also when you get the uppipe make sure you have the right number of bolt studs for the install...some had to add in some to install it from the stock WRX uppipe.
FYI...also when you get the uppipe make sure you have the right number of bolt studs for the install...some had to add in some to install it from the stock WRX uppipe.
Registered User
iTrader: (2)
Joined: Jul 2005
Posts: 147
From: The Wild Serengeti Suburbs of MAIC
Car Info: '08 WRB SG model D
Originally Posted by lastlaugh
I've had my uppipe for a while now. Just got a factory one and gutted it.
Thread
Thread Starter
Forum
Replies
Last Post
srbaugust
General Tech / How To's / Installations
15
Jun 2, 2013 02:02 AM
flatline
NorCal Classifieds
17
Aug 3, 2008 11:38 AM
1FSTREX
Sacramento & Reno
17
Oct 2, 2007 07:22 AM
casualsurfer
Engine/Power - EJ20T (pre-2006 WRX and JDM)
9
May 3, 2004 03:24 PM
willow
Engine/Power - EJ20T (pre-2006 WRX and JDM)
5
Mar 13, 2004 08:41 AM
